Again: Unleaded or leaded fuel for mid 70's /6?

Killer6 said
What is the prospective test mill?

I can’t say but we made two quick pulls and at first glance the AV gas is making the same power as Sunoco 110 and it’s a damn sight cheaper.

Its colder than a well diggers *** outside so in the morning I’ll pull the plugs and get a look.